I wonder if soaking the cans in a caustic soda solution would not get the same results without pressure cooking . Caustic soda needs to be handled carefully but is very useful for stripping paint . It is a key ingredient in paint stripper . I would immerse the cans in a plastic bucket and cover them with a solution of caustic soda and warm water for a few hours and then rinse them in clean water afterwards .

You know ... Something tells me that someone is going to try this .. Despite the warnings ... Ok . So when half of Kentucky gets "blowed up " .. We know who tried it ! Still an interesting idea .

HeHeHe ... Have not laughed like this for days .. Budding freedom fighters and exploding glass jars with visions of blackened faces and singed hair of kitchen and backyard scientists .. Thanks all .. You made my day ! .

Here is a very handy use for pencils which you have not listed . Pencil graphite , the lead , is an excellent lubricant . If you have a sticky key or door lock , run the pencil graphite tip along the edge that makes contact on the lock or along the ridges of a key and see how easily it slides in after that . Rub a pencil on a piece of sandpaper to make graphite dust , fold a piece of paper with the graphite inside and put it to a sticky lock key hole and gently blow the graphite dust into the lock . Then try the key a few times and it immediately starts working more smoothly . Graphite powder is dry and does not cause dust to stick to it like oil so it is very good for fine mechanisms like locks but it also works on slide rails , wheels etc .